German Chancellor Angela Merkel, right, talks with former Sen. Chuck Hagel, R-Neb., current chairman of the Atlantic Council of the United States, as she arrives to receive the Eric M. Warburg Award at the Library of Congress in Washington, Thursday, June 25, 2009. (AP Photo/Gerald Herbert)

WASHINGTON (Reuters) - President Barack Obama offered strong support for former Republican Senator Chuck Hagel as the potential next U.S. defense secretary but said in remarks aired on Sunday that he had not yet decided on a nominee for the Pentagon post.

Hagel is considered a leading candidate to replace outgoing Secretary of Defense Leon Panetta, but the former Nebraska lawmaker has come under criticism for his record on Israel and for a comment that being gay was an inhibiting factor for being an ambassador.

"I've served with Chuck Hagel. I know him. He is a patriot. He is somebody who has done extraordinary work both in the United States Senate, somebody who served this country with valor in Vietnam," Obama told NBC's "Meet the Press" in an interview taped on Saturday and broadcast on Sunday.

Any nomination for defense secretary must be approved by the Senate where some lawmakers have voiced criticism about their former colleague.

"I think a lot of Republicans and Democrats are very concerned about Chuck Hagel's positions on Iran sanctions, his views toward Israel, Hamas and Hezbollah, and that there is wide and deep concern about his policies. All of us like him as a person," Republican Senator Lindsey Graham said.

"There would be very little Republican support for his nomination, at the end of the day, there will be very few votes," Graham said on Fox News Sunday.

Aside from his controversial statements, "he does not have the experience to manage a very large organization like the Pentagon," Coburn said on CBS' "Face the Nation." "If there's a place that we need great management it's the Pentagon."

Senator Richard Durbin, a Democrat from Illinois, said on the same television show that Hagel deserved "respect for the service he's given our country in the military and in the Senate" and should be given consideration. "He at least deserves a hearing and an opportunity," he said.

Obama said he had seen nothing that would disqualify Hagel.

The president said Hagel had apologized for his comments related to homosexuality, referred to by NBC's David Gregory in the interview.

"With respect to the particular comment that you quoted, he apologized for it," Obama said.

"And I think it's a testimony to what has been a positive change over the last decade in terms of people's attitudes about gays and lesbians serving our country. And that's something that I'm very proud to have led," he said.

Obama came out in favor of gay marriage in the middle of his re-election bid this year. Earlier in his term he presided over the end of the "don't ask, don't tell" policy that prohibited gay men and women from serving openly in the U.S. military.

Hagel, who left the Senate in 2008, has faced questions about his record on Israel.

Some of Israel's leading U.S. supporters contend that Hagel at times opposed Israel's interests, voting several times against U.S. sanctions on Iran, and made disparaging remarks about the influence of what he called a "Jewish lobby" in Washington.

Obama, who has strained relations with Israeli Prime Minister Benjamin Netanyahu, has faced questions of his own from the American Jewish community about his approach to the U.S. ally.

Obama said Hagel was doing an "outstanding job" serving on an intelligence advisory board and gave no indication on when he would make his final decision about the defense chief job.

The president has already backed down once from a contentious nomination, choosing Democratic Senator John Kerry to replace Hillary Clinton as secretary of state rather than going with his presumed first choice, U.S. Ambassador to the United Nations Susan Rice, whom many Republicans opposed after she made controversial remarks about the September 11 attacks on a U.S. mission in Benghazi, Libya, that killed four Americans.